Johnson P J, Leung N, Cheng P, Welby C, Leung W T, Lau W Y, Yu S, Ho S
Hepatoma Study Group, Sir YK Pao Cancer Centre, Shatin, NT, Hong Kong.
Br J Cancer. 1997;75(2):236-40. doi: 10.1038/bjc.1997.39.
The only hope for effective treatment of hepatocellular carcinoma (HCC or 'hepatoma') lies in early diagnosis. Measurement of the serum alphafetoprotein (AFP) level is potentially a useful screening test. When grossly raised, it is almost diagnostic of HCC. However, modestly elevated levels may also arise in patients with benign chronic liver disease, and this markedly decreases the test's specificity and hence its clinical value. In 582 consecutive attendees at an outpatient clinic for people with chronic liver disease, a single blood sample was taken for analysis of 'total' AFP and the 'hepatoma-specific' AFP isoform. Using ultrasonography as the primary screening method, patients with AFP levels > or = 50 ng ml-1 were followed up throughout the study or until HCC was diagnosed on the basis of conventionally defined criteria. On entry into the study, 53 patients had an AFP concentration > = or 50 ng ml-1 and the 'hepatoma-specific' AFP isoform was detected in 26 of these. During an 18-month follow-up period, a diagnosis of HCC was established by conventional methods in 19 (17 'definite' and two 'probable') of these 26 patients. In only two cases was there ultrasound evidence of tumour development at the time AFP was first found to be elevated; in the remainder a diagnosis of HCC, based on ultrasound screening, was established at a median time of 3.6 months (range 1-18 months) after entry into the study. Among those 27 without the 'hepatoma-specific' isoform, one developed a 'definite' HCC and two developed 'probable' tumours. With the application of 'hepatoma-specific' AFP, the positive predictive value of the test was 73.1%, compared with only 41.5% using the conventional 'total' AFP test. Application of this test for the 'hepatoma-specific' AFP markedly increases the positive predictive value of AFP and, in some cases, permits the presence of tumour to be inferred before it could be detected by routine ultrasound examination.
肝细胞癌（HCC 或“肝癌”）有效治疗的唯一希望在于早期诊断。血清甲胎蛋白（AFP）水平的检测可能是一种有用的筛查试验。当AFP水平大幅升高时，几乎可诊断为HCC。然而，良性慢性肝病患者的AFP水平也可能适度升高，这显著降低了该检测的特异性，进而降低了其临床价值。在一家慢性肝病门诊的582名连续就诊者中，采集一份血样用于分析“总”AFP和“肝癌特异性”AFP异构体。以超声检查作为主要筛查方法，AFP水平≥50 ng/ml的患者在整个研究过程中接受随访，或直至根据传统定义标准诊断为HCC。在进入研究时，53名患者的AFP浓度≥50 ng/ml，其中26名检测到“肝癌特异性”AFP异构体。在18个月的随访期内，这26名患者中有19名（17名“确诊”和2名“疑似”）通过传统方法确诊为HCC。在AFP首次被发现升高时，仅有2例有超声证据显示肿瘤进展；其余患者在进入研究后的中位时间3.6个月（范围1 - 18个月）通过超声筛查确诊为HCC。在未检测到“肝癌特异性”异构体的27名患者中，1名发展为“确诊”HCC，2名发展为“疑似”肿瘤。应用“肝癌特异性”AFP检测时，该检测的阳性预测值为73.1%，而使用传统的“总”AFP检测时仅为41.5%。应用这种“肝癌特异性”AFP检测可显著提高AFP的阳性预测值，在某些情况下，还能在常规超声检查发现肿瘤之前推断肿瘤的存在。
